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April 2010 arXiv papers — page 10

Showing 9011,000 of 5,597 papers

  1. L. Jin, Z. Song

    We study the formation and dynamics of the bound pair (BP) and bound triple (BT) in strongly correlated extended Hubbard model for both Bose and Fermi systems. We find that the bandwidths of the BP and BT gain significantly when the on-site and nearest-neighbor interaction strengths reach the corresponding resonant points. This allows the fast transfer and e

  2. Nikolay P. Vabishchevich, Petr N. Vabishchevich

    Mathematical physics problems are often formulated using differential oprators of vector analysis - invariant operators of first order, namely, divergence, gradient and rotor operators. In approximate solution of such problems it is natural to employ similar operator formulations for grid problems, too. The VAGO (Vector Analysis Grid Operators) method is bas

  3. John D Barrow, Kei Yamamoto

    We show that the inclusion of simple anisotropic pressures stops the isotropic Friedmann universe being a stable attractor as an initial or final singularity is approached when pressures can exceed the energy density. This shows that the situation with isotropic pressures, studied earlier in the context of cyclic and ekpyrotic cosmologies, is not generic, an

  4. Ronaldo Bellazzini, Fabio Muleri

    Polarimetry is widely considered a powerful observational technique in X-ray astronomy, useful to enhance our understanding of the emission mechanisms, geometry and magnetic field arrangement of many compact objects. However, the lack of suitable sensitive instrumentation in the X-ray energy band has been the limiting factor for its development in the last t

  5. Avery Meiksin, Eric R. Tittley, Calum K. Brown

    We examine the temperature structure of the intergalactic medium IGM) surounding a hard radiation source, such as a Quasi-Stellar Object (QSO), as it responds to the onset of helium reionization by the source. We model the reionization using a radiative transfer (RT) code coupled to a particle-mesh (PM) N-body code. Neutral hydrogen and helium are initially

  6. Fiammetta Battaglia

    We compute the Betti numbers of the geometric spaces associated to nonrational simple convex polytopes and find that they depend on the combinatorial type of the polytope exactly as in the rational case. This shows that the combinatorial features of the starting polytope are encoded in these generalized toric spaces as they are in their rational counterparts

  7. Ivan Kyrchei

    In this article, we introduce determinantal representations of the Moore - Penrose inverse and the Drazin inverse which are based on analogues of the classical adjoint matrix. Using the obtained analogues of the adjoint matrix, we get Cramer rules for the least squares solution and for the Drazin inverse solution of singular linear systems. Finally, determin

  8. A. Ya. Bekshaev, S. V. Sviridova

    Spatial characteristics of diffracted beams produced by a "fork" hologram from an incident circular Laguerre-Gaussian beam whose axis differ from the hologram optical axis are studied theoretically. General analytical representations for the complex amplitude distribution of a diffracted beam are derived in terms of superposition of Kummer beams or h

  9. Mikkel Baun Kjærgaard

    An increasingly important requirement for many novel applications is sensing the positions of people, equipment, etc. GPS technology has proven itself as a successfull technology for positioning in outdoor environments but indoor no technology has yet gained a similar wide-scale adoption. A promising indoor positioning technique is radio-based location finge

  10. Sudarshan Shinde

    In this paper we present a method to design paraunitary polyphase matrices of critically sampled rational filter banks. The method is based on (P,Q) shift-invariant systems, and so any kind of rational splitting of the frequency spectrum can be achieved using this method. Ideal (P,Q) shift-invariant system with smallest P and Q that map of a band of input sp

  11. J. van Eymeren, B. S. Koribalski, A. R. Lopez-Sanchez, R. -J. Dettmar

    Abridged. The feedback between massive stars and the interstellar medium is one of the most important processes in the evolution of dwarf galaxies. This interaction results in numerous neutral and ionised gas structures that have been found both in the disc and in the halo of these galaxies. However, their origin and fate are still poorly understood. We here

  12. F. Stivoli, J. Grain, S. M. Leach, M. Tristram

    We investigate the performance of the parametric Maximum Likelihood component separation method in the context of the CMB B-mode signal detection and its characterization by small-scale CMB suborbital experiments. We consider high-resolution (FWHM=8') balloon-borne and ground-based observatories mapping low dust-contrast sky areas of 400 and 1000 square

  13. R. J. Collins, P. J. Clarke, V. Fernandez, K. J. Gordon

    A demonstration of the principles of quantum key distribution is performed using a single-photon source in a proof of concept test-bed over a distance of 2 km in standard telecommunications optical fiber. The single-photon source was an optically-pumped quantum dot in a microcavity emitting at a wavelength of 895 nm. Characterization of the quantum key distr

  14. Isabel Fernandez, Pablo Mira

    This is a survey on the global theory of constant mean curvature surfaces in Riemannian homogeneous 3-manifolds. These ambient 3-manifolds include the eight canonical Thurston 3-dimensional geometries, i.e. R3, H3, S3, H2 \times R, S2 \times R, the Heisenberg space Nil3, the universal cover of PSL2(R) and the Lie group Sol3. We will focus on the problems of

  15. Nam Hoon Lee, Soon-Gil Jung, Dong Ho Kim, Won Nam Kang

    We report the growth of potassium-doped BaFe2As2 thin films, where the major charge carriers are holes, on Al2O3 (0001) and LaAlO3 (001) substrates by using an ex-situ pulsed laser deposition technique. The measured Tc's are 40 and 39 K for the films grown on Al2O3 and LaAlO3, respectively and diamagnetism indicates that the films have good bulk supercon

  16. Xiangdi Huang, Jing Li, Zhouping Xin

    We extend the well-known Serrin's blowup criterion for the three-dimensional (3D) incompressible Navier-Stokes equations to the 3D viscous compressible cases. It is shown that for the Cauchy problem of the 3D compressible Navier-Stokes system in the whole space, the strong or smooth solution exists globally if the velocity satisfies the Serrin's cond

  17. P. C. van der Kruit

    In this review I concentrate on three areas related to structure of disks in spiral galaxies. First I will review the work on structure, kinematics and dynamics of stellar disks. Next I will review the progress in the area of flaring of HI layers. These subjects are relevant for the presence of dark matter and lead to the conclusion that disk are in general

  18. L. Lepori, G. Mussardo, A. Trombettoni

    We propose the experimental realization of (3+1) relativistic Dirac fermions using ultracold atoms in a rotating optical lattice or, alternatively, in a synthetic magnetic field. This approach has the advantage to give mass to the Dirac fermions by coupling the ultracold atoms to a Bragg pulse. A dimensional crossover from (3+1) to (2+1) Dirac fermions can b

  19. J. J. Brey, M. I. Garcia de Soria, P. Maynar

    Both the right and left eigenfunctions and eigenvalues of the linearized homogeneous Boltzmann equation for inelastic Maxwell molecules corresponding to the hydrodynamic modes are calculated. Also, some non-hydrodynamic modes are identified. It is shown that below a critical value of the parameter characterizing the inelasticity, one of the kinetic modes dec

  20. Hiroki Nakamura, Masahiko Machida

    We calculate electronic structures of a high-Tc iron-based superconductor Sr2VFeAsO3 by LDA+U method. We assume a checker-board antiferromagnetic order on blocking layers including vanadium and strong correlation in d-orbits of vanadium through the Hubbard U. While the standard LDA brings about metallic blocking layers and complicated Fermi surface as in the

  21. V. Viasnoff, U. Bockelmann, A. Meller, H. Isambert

    We provide an experimental demonstration that the focusing of ionic currents in a micron size hole connecting two chambers can produce local temperature increases of up to $100^\circ$ C with gradients as large as $1^\circ$ K$μm^{-1}$. We find a good agreement between the measured temperature profiles and a finite elements-based numerical calculation. We show

  22. Christian Rehwald, Nicoletta Gnan, Andreas Heuer, Thomas Schrøder

    We present molecular dynamics simulations of a model glass-forming liquid (the binary Kob-Anderson Lennard-Jones model) and consider the distributions of inherent energies and metabasins during aging. In addition to the typical protocol of performing a temperature jump from a high temperature to a low destination temperature, we consider the temporal evoluti

  23. Martin Josef Geiger

    On the basis of an analysis of previous research, we present a generalized approach for measuring the difference of plans with an exemplary application to machine scheduling. Our work is motivated by the need for such measures, which are used in dynamic scheduling and planning situations. In this context, quantitative approaches are needed for the assessment

  24. D. Kaczorowski, A. P. Pikul, U. Burkhardt, M. Schmidt

    The crystal structures and the physical (magnetic, electrical transport and thermodynamic) properties of the ternary compounds CeRhSi2 and Ce2Rh3Si5 (orthorhombic CeNiSi2- and U2Co3Si5-type structures, respectively) were studied in wide ranges of temperature and magnetic field strength. The results revealed that both materials are valence fluctuating systems

  25. Venkatesan T. Chakaravarthy, Vinayaka Pandit, Yogish Sabharwal

    We study the problem of anonymizing tables containing personal information before releasing them for public use. One of the formulations considered in this context is the $k$-anonymization problem: given a table, suppress a minimum number of cells so that in the transformed table, each row is identical to atleast $k-1$ other rows. The problem is known to be

  26. G. Ambrosetti, C. Grimaldi, I. Balberg, T. Maeder

    We noted that the tunneling-percolation framework is quite well understood at the extreme cases of percolation-like and hopping-like behaviors but that the intermediate regime has not been previously discussed, in spite of its relevance to the intensively studied electrical properties of nanocomposites. Following that we study here the conductivity of disper

  27. Itai Benjamini, Panos Papasoglu

    Let G be a planar graph such that the volume function of G satisfies V(2n)< CV(n) for some constant C > 0. Then for every vertex v of G and integer n, there is a domain Ωsuch that B(v,n) \subset Ω, Ω\subset B(v, 6n) and the size of the boundary of Ωis at most order n.

  28. Alexei Davydov, Liang Kong, Ingo Runkel

    Given two two-dimensional conformal field theories, a domain wall -- or defect line -- between them is called invertible if there is another defect with which it fuses to the identity defect. A defect is called topological if it is transparent to the stress tensor. A conformal isomorphism between the two CFTs is a linear isomorphism between their state space

  29. Olivier Debarre, Atanas Iliev, Laurent Manivel

    We study the geometry and the period map of nodal complex prime Fano threefolds with index 1 and degree 10. We show that these threefolds are birationally isomorphic to Verra solids (hypersurfaces of bidegree $(2,2)$ in $ ¶^2\times ¶^2$). Using Verra&#39;s results on the period map for these solids and on the Prym map for double étale covers of plane sextic

  30. Adrien Dubouloz, Lucy Moser-Jauslin, Pierre-Marie Poloni

    We construct two non isomorphic contractible affine threefolds X and Y with isomorphic cylinders, showing that the generalized Cancellation Problem has a negative answer in general for contractible affine threefolds. We also establish that X and Y are actually biholomorphic as complex analytic varieties, providing the first example of a pair of biholomorphic

  31. David Prévost, Sylvain Lavernhe, Claire Lartigue

    This paper deals with an advanced modeling of the feed drives of a five axis machine tool within the context of High Speed Machining. The management of the multi axes as well as high velocities causes problems to the set machine tool - Numerical Controller throughout the trajectory execution process. As a result, many errors are introduced during machining a

  32. Manami Sasaki, Dmitry Klochkov, Ute Kraus, Isabel Caballero

    The pulse profiles of the transient Be/X-ray binary EXO 2030+375 show strong dependence on energy, as well as on its luminosity state, and are asymmetric in shape. We want to identify the emission components of the two magnetic poles in the pulsed emission to understand the geometry of the neutron star and its beam pattern. We utilize a pulse-profile decompo

  33. Woong-Kee Loh, Yang-Sae Moon, Jun-Gyu Kang

    In this paper, we emphasize the need for data cleansing when clustering large-scale transaction databases and propose a new data cleansing method that improves clustering quality and performance. We evaluate our data cleansing method through a series of experiments. As a result, the clustering quality and performance were significantly improved by up to 165%

  34. V. F. Dmitriev, A. I. Milstein, S. G. Salnikov

    Low energy $p\bar{p}$ interaction is considered taking into account the polarization of both particles. The corresponding cross sections are calculated using the Nijmegen nucleon-antinucleon optical potential. Then they are applied to the analysis of the polarization buildup which is due to the interaction of stored antiprotons with polarized protons of a hy

  35. T. A. Platova, I. R. Mukhamedshin, A. V. Dooglav, H. Alloul

    We have investigated a set of sodium cobaltates (NaxCoO2) samples with various sodium content (0.67 \le x \le 0.75) using Nuclear Quadrupole Resonance (NQR). The four different stable phases and an intermediate one have been recognized. The NQR spectra of 59Co allowed us to clearly differentiate the pure phase samples which could be easily distinguished from

  36. Kenneth W. Shum, Wing Shing Wong

    Protocol sequences are used in channel access for the multiple-access collision channel without feedback. A new construction of protocol sequences with a guarantee of worst-case system throughput is proposed. The construction is based on Chinese remainder theorem. The Hamming crosscorrelation is proved to be concentrated around the mean. The sequence period

  37. Ryu Sasaki

    Brief introduction to the discrete quantum mechanics is given together with the main results on various exactly solvable systems. Namely, the intertwining relations, shape invariance, Heisenberg operator solutions, annihilation/creation operators, dynamical symmetry algebras including the $q$-oscillator algebra and the Askey-Wilson algebra. A simple recipe t

  38. Ryu Sasaki, Satoshi Tsujimoto, Alexei Zhedanov

    Simple derivation is presented of the four families of infinitely many shape invariant Hamiltonians corresponding to the exceptional Laguerre and Jacobi polynomials. Darboux-Crum transformations are applied to connect the well-known shape invariant Hamiltonians of the radial oscillator and the Darboux-Pöschl-Teller potential to the shape invariant potentials

  39. Michael T. Goodrich

    In this paper, we describe efficient MapReduce simulations of parallel algorithms specified in the BSP and PRAM models. We also provide some applications of these simulation results to problems in parallel computational geometry for the MapReduce framework, which result in efficient MapReduce algorithms for sorting, 1-dimensional all nearest-neighbors, 2-dim

  40. Takashi Hotta

    We provide a prescription to construct a microscopic model for heavy lanthanide systems such as Yb and Tm compounds by exploiting a $j$-$j$ coupling scheme. Here we consider a situation with a large spin-orbit coupling, in which $j$=5/2 sextet is fully occupied, while $j$=7/2 octet is partially occupied, where $j$ denotes total angular momentum. We evaluate

  41. Alexandru Ghitza

    We revisit a theorem of Ram Murty about the number of initial Fourier coefficients that two cuspidal eigenforms of different weights can have in common. We prove an explicit upper bound on this number, and give better conditional and unconditional asymptotic upper bounds. Finally, we describe a numerical experiment testing the sharpness of the upper bound in

  42. Woo Kyun Kim, Michael L. Falk

    Reformulating hyperdynamics without using a transition state theory (TST) dividing surface makes it possible to accelerate conventional molecular dynamics (MD) simulation using a broader range of bias potentials. A new scheme to calculate the boost factor is also introduced that makes the hyperdynamics method more accurate and efficient. Novel bias potential

  43. Eric E. Mamajek

    Greaves (2006) proposed that three red, high proper motion stars within 10 degrees of 51 Peg (NLTT 54007, 54064, & 55547) are co-moving companions to this famous exoplanet host star. While the stars clearly have proper motions similar to 51 Peg, the inferred kinematic parallaxes for these stars produce extremely inconsistent color-magnitude positions 2 to 4

  44. Abderezak Ould Houcine

    We show that any nonabelian free group $F$ of finite rank is homogeneous; that is for any tuples $\bar a$, $\bar b \in F^n$, having the same complete $n$-type, there exists an automorphism of $F$ which sends $\bar a$ to $\bar b$. We further study existential types and we show that for any tuples $\bar a, \bar b \in F^n$, if $\bar a$ and $\bar b$ have the sam

  45. Abdul H. Mroué, Harald P. Pfeiffer, Lawrence E. Kidder, Saul A. Teukolsky

    We compare different methods of computing the orbital eccentricity of quasi-circular binary black hole systems using the orbital variables and gravitational wave phase and frequency. For eccentricities of about a per cent, most methods work satisfactorily. For small eccentricity, however, the gravitational wave phase allows a particularly clean and reliable

  46. Richard R. Lane, László L. Kiss, Geraint F. Lewis, Rodrigo A. Ibata

    Globular clusters have proven to be essential to our understanding of many important astrophysical phenomena. Here we analyse spectroscopic observations of ten Halo globular clusters to determine their dark matter content, their tidal heating by the Galactic disc and halo, describe their metallicities and the likelihood that Newtonian dynamics explain their

  47. Na Fu, Weixing Shu, Hailu Luo, Zhixiang Tang

    A type of 3-dimensional optical negative-refractive-index metamaterials composed of all dielectric nanospheres is proposed and demonstrated theoretically. The metamaterials are constructeded by pairing together two kinds of dielectric nanospheres as concentric shells embedded in a host medium. Mie-based extended effective theory shows that the dielectric cor

  48. Xian-Min Jin, Jian Yang, Han Zhang, Han-Ning Dai

    Photonic entanglement source and quantum memory are two basic building blocks of linear-optical quantum computation and long-distance quantum communication. In the past decades, intensive researches have been carried out, and remarkable progress, particularly based on the spontaneous parametric down-converted (SPDC) entanglement source and atomic ensembles,

  49. Weiping Zhu

    For the tree topology, previous studies show the maximum likelihood estimate (MLE) of a link/path takes a polynomial form with a degree that is one less than the number of descendants connected to the link/path. Since then, the main concern is focused on searching for methods to solve the high degree polynomial without using iterative approximation. An expli

  50. Robert A Malaney

    Recently it has been shown how the use of quantum entanglement can lead to the creation of real-time communication channels whose viability can be made location dependent. Such functionality leads to new security paradigms that are not possible in classical communication networks. Key to these new security paradigms are quantum protocols that can uncondition

  51. B. Moritz, T. P. Devereaux, J. K. Freericks

    In this work we examine the time-resolved, instantaneous current response for the spinless Falicov-Kimball model at half-filling, on both sides of the Mott-Hubbard metal-insulator transition, driven by a strong electric field pump pulse. The results are obtained using an exact, nonequilibrium, many-body impurity solution specifically designed to treat the ou

  52. Douglas H. Kelley, Nicholas T. Ouellette

    We present a method for reconstructing two-dimensional velocity fields at specified length scales using observational data from tracer particles in a flow, without the need for interpolation or smoothing. The algorithm, adapted from techniques proposed for oceanography, involves a least-squares projection of the measurements onto a set of two-dimensional, in

  53. Radhendushka Srivastava, Debasis Sengupta

    A practical constraint that comes in the way of spectrum estimation of a continuous time stationary stochastic process is the minimum separation between successively observed samples of the process. When the underlying process is not band-limited, sampling at any uniform rate leads to aliasing, while certain stochastic sampling schemes, including Poisson pro

  54. B. Moritz, S. Johnston, T. P. Devereaux

    Recently, angle-resolved photoemission spectroscopy has been used to highlight an anomalously large band renormalization at high binding energies in cuprate superconductors: the high energy &#34;waterfall&#34; or high energy anomaly (HEA). The anomaly is present for both hole- and electron-doped cuprates as well as the half-filled parent insulators with diff

  55. H. Ebeling, A. C. Edge, A. Mantz, E. Barrett

    We present a statistically complete sample of very X-ray luminous galaxy clusters detected in the MAssive Cluster Survey (MACS). This second MACS release comprises all 34 MACS clusters with nominal X-ray fluxes in excess of 2x10^(-12) erg/s/cm^2 (0.1-2.4 keV) in the ROSAT Bright Source Catalogue; two thirds of them are new discoveries. Extending over the red

  56. Ruilong Liu

    In this paper, we investigate a novel $(2,2)$-threshold scheme and then generalize this to a $(n,n)$-threshold scheme for quantum secret sharing (QSS) which makes use of the fundamentals of Analytic Geometry. The dealer aptly selects GHZ states related to the coefficients which determine straight lines on a two-dimension plane. Then by computing each two of

  57. C. Ogle

    Using techniques developed for studying polynomially bounded cohomology, we show that the assembly map for $K_*^t(\ell^1(G))$ is rationally injective for all finitely presented discrete groups $G$. This verifies the $\ell^1$-analogue of the Strong Novikov Conjecture for such groups.

  58. Charo I. Del Genio, Kevin E. Bassler

    We study a continuous quasi-two-dimensional order-disorder phase transition that occurs in a simple model of a material that is inhomogeneously strained due to the presence of dislocation lines. Performing Monte Carlo simulations of different system sizes and using finite size scaling, we measure critical exponents describing the transition of beta=0.18\pm0.

  59. Myung Joon Han, Chris A. Marianetti, Andrew J. Millis

    The application of modern layer-by-layer growth techniques to transition-metal oxide materials raises the possibility of creating new classes of materials with rationally designed correlated electron properties. An important step toward this goal is the demonstration that electronic structure can be controlled by atomic composition. In compounds with partial

  60. R. Ji, C. Ogle, B. Ramsey

    A discrete group with word-length (G,L) is B-isocohomological for a bounding classes B if the comparison map from B-bounded cohomology to ordinary cohomology (with complex coefficients) is an isomorphism; it is strongly B-isocohomological if the same is true with arbitrary coefficients. In this paper we establish some basic conditions guaranteeing strong B-i

  61. P. Popovich, M. V. Umansky, T. A. Carter, B. Friedman

    The properties of linear instabilities in the Large Plasma Device [W. Gekelman et al., Rev. Sci. Inst., 62, 2875 (1991)] are studied both through analytic calculations and solving numerically a system of linearized collisional plasma fluid equations using the 3D fluid code BOUT [M. Umansky et al., Contrib. Plasma Phys. 180, 887 (2009)], which has been succes

  62. Lie-Wen Chen, Che Ming Ko, Bao-An Li, Jun Xu

    Expressing explicitly the parameters of the standard Skyrme interaction in terms of the macroscopic properties of asymmetric nuclear matter, we show in the Skyrme-Hartree-Fock approach that unambiguous correlations exist between observables of finite nuclei and nuclear matter properties. We find that existing data on neutron skin thickness $Δr_{np}$ of Sn is

  63. Alexey Kuznetsov, Andreas E. Kyprianou, Juan Carlos Pardo

    The last couple of years has seen a remarkable number of new, explicit examples of the Wiener-Hopf factorization for Levy processes where previously there had been very few. We mention in particular the many cases of spectrally negative Levy processes, hyper-exponential and generalized hyper-exponential Levy processes, Lamperti-stable processes, Hypergeometr

  64. Jesse Johnson

    We show that given a partially flat angled ideal triangulation for a 3-manifold $M$ with boundary (as defined by Lackenby), there is an algorithm to produce a list of Heegaard splittings for $M$ such that below a given genus $g$, each isotopy class appears exactly once. In particular, this algorithm determines precisely when two almost normal surfaces repres

  65. Nick S. Jones, John Moriarty

    Biological data objects often have both of the following features: (i) they are functions rather than single numbers or vectors, and (ii) they are correlated due to phylogenetic relationships. In this paper we give a flexible statistical model for such data, by combining assumptions from phylogenetics with Gaussian processes. We describe its use as a nonpara

  66. Amine Asselah, Alexandre Gaudilliere

    We consider a cluster growth model on Z^d, called internal diffusion limited aggregation (internal DLA). In this model, random walks start at the origin, one at a time, and stop moving when reaching a site not occupied by previous walks. It is known that the asymptotic shape of the cluster is spherical. Also, when dimension is 2 or more, and when the cluster

  67. Guozhu Sun, Xueda Wen, Bo Mao, Zhongyuan Zhou

    We present an analytical and comprehensive description of the quantum dynamics of a microwave resonantly driven superconducting phase qubit coupled to a microscopic two-level system (TLS), covering a wide range of the external microwave field strength. Our model predicts several interesting phenomena in such an ac driven four-level bipartite system including

  68. Yong-Qiang Wang, Yu-Xiao Liu

    We investigate the hidden conformal symmetry of the 4-dimensional non-extremal Kerr-Newman (KN) black hole with the idea of the near-region Kerr/CFT correspondence proposed by Castro, Maloney and Strominger in arXiv:1004.0996[hep-th]. The near-region KN black hole is dual to a 2D CFT with left and right temperatures $T_L=(2 M^2-Q^2)/(4πJ)$ and $T_R=\sqrt{M^4

  69. Adi Zitrin, Tom Broadhurst, Keiichi Umetsu, Yoel Rephaeli

    The inner mass-profile of the relaxed cluster Abell 1703 is analysed by two very different strong-lensing techniques applied to deep ACS and WFC3 imaging. Our parametric method has the accuracy required to reproduce the many sets of multiple images, based on the assumption that mass approximately traces light. We test this assumption with a fully non-paramet

  70. Marcelo Gleiser, Noah Graham, Nikitas Stamatopoulos

    Through a detailed numerical investigation in three spatial dimensions, we demonstrate that long-lived time-dependent field configurations emerge dynamically during symmetry breaking in an expanding de Sitter spacetime. We investigate two situations: a single scalar field with a double-well potential and the bosonic sector of an SU(2) non-Abelian Higgs model

  71. Guozhu Sun, Xueda Wen, Bo Mao, Jian Chen

    Coherent control of quantum states is at the heart of implementing solid-state quantum processors and testing quantum mechanics at the macroscopic level. Despite significant progress made in recent years in controlling single- and bi-partite quantum systems, coherent control of quantum wave function in multipartite systems involving artificial solid-state qu

  72. Krzysztof R. Apt, Frank S. de Boer, Ernst-Ruediger Olderog, Stijn de Gouw

    We show that verification of object-oriented programs by means of the assertional method can be achieved in a simple way by exploiting a syntax-directed transformation from object-oriented programs to recursive programs. This transformation suggests natural proofs rules and its correctness helps us to establish soundness and relative completeness of the prop

  73. José P. S. Lemos, Oleg B. Zaslavskii

    A quasiblack hole is an object in which its boundary is situated at a surface called the quasihorizon, defined by its own gravitational radius. We elucidate under which conditions a quasiblack hole can form under the presence of matter with nonzero pressure. It is supposed that in the outer region an extremal quasihorizon forms, whereas inside, the quasihori

  74. Stjepan Meljanac, Sasa Kresic-Juric

    We construct realizations of the generators of the $κ$-Minkowski space and $κ$-Poincaré algebra as formal power series in the $h$-adic extension of the Weyl algebra. The Hopf algebra structure of the $κ$-Poincaré algebra related to different realizations is given. We construct realizations of the exterior derivative and one-forms, and define a differential c

  75. Liviu Ornea, Misha Verbitsky

    A manifold $M$ is locally conformally Kahler (LCK) if it admits a Kahler covering with monodromy acting by holomorphic homotheties. Let $M$ be an LCK manifold admitting a holomorphic conformal flow of diffeomorphisms, lifted to a non-isometric homothetic flow on its covering. We show that $M$ admits an automorphic potential. This version was added 10 years a

  76. S. E. Nuza, K. Dolag, A. Saro

    In this work, we present results for the photometric and clustering properties of galaxies that arise in a LambdaCDM hydrodynamical simulation of the local universe. The present-day distribution of matter was constructed to match the observed large scale pattern of the IRAS 1.2-Jy galaxy survey. Our simulation follows the formation and evolution of galaxies

  77. Daniel S. Roche

    Finding the product of two polynomials is an essential and basic problem in computer algebra. While most previous results have focused on the worst-case complexity, we instead employ the technique of adaptive analysis to give an improvement in many &#34;easy&#34; cases. We present two adaptive measures and methods for polynomial multiplication, and also show

  78. Martin Crocce, Anna Cabre, Enrique Gaztañaga

    Near future cosmology will see the advent of wide area photometric galaxy surveys, like the Dark Energy Survey (DES), that extent to high redshifts (z ~ 1 - 2) but with poor radial distance resolution. In such cases splitting the data into redshift bins and using the angular correlation function $w(θ)$, or the $C_{\ell}$ power spectrum, will become the stand

  79. A. Bershadskii

    It is shown that, the wavelet regression detrended fluctuations of the monthly sunspot number for 1749-2009 years exhibit strong periodicity with a period approximately equal to 3.7 years. The wavelet regression method detrends the data from the approximately 11-years period. Therefore, it is suggested that the one-third subharmonic resonance can be consider

  80. Clifford Cheung, Jeremy Mardon, Yasunori Nomura, Jesse Thaler

    If the lightest observable-sector supersymmetric particle (LOSP) is charged and long-lived, then it may be possible to indirectly measure the Planck mass at the LHC and provide a spectacular confirmation of supergravity as a symmetry of nature. Unfortunately, this proposal is only feasible if the gravitino is heavy enough to be measured at colliders, and thi

  81. Pavel Etingof, Travis Schedler

    We compute the space of Poisson traces on a classical W-algebra modulo an arbitrary central character, i.e., linear functionals on such an algebra invariant under Hamiltonian derivations. This space identifies with the top cohomology of the corresponding Springer fiber. As a consequence, we deduce that the zeroth Hochschild homology of the corresponding quan

  82. Helvi Witek, Vitor Cardoso, Carlos Herdeiro, Andrea Nerozzi

    The evolution of black holes in &#34;confining boxes&#34; is interesting for a number of reasons, particularly because it mimics the global structure of Anti-de Sitter geometries. These are non-globally hyperbolic space-times and the Cauchy problem may only be well defined if the initial data is supplemented by boundary conditions at the time-like conformal

  83. D. I. Tsomokos, T. J. Osborne, C. Castelnovo

    We analyze the toric code model in the presence of quenched disorder, which is introduced via different types of random magnetic fields. In general, close to a quantum phase transition between a spin polarized phase and a topologically ordered one, we find that increasing the amount of disorder favors the topological phase. For some realizations of disorder,

  84. Bohm-Jung Yang, Yong Baek Kim

    The possible existence of topological insulators in cubic pyrochlore iridates A$_{2}$Ir$_{2}$O$_{7}$ (A = Y or rare-earth elements) is investigated by taking into account the strong spin-orbit coupling and trigonal crystal field effect. It is found that the trigonal crystal field effect, which is always present in real systems, may destabilize the topologica

  85. Johannes Bergstrom, Michal Malinsky, Tommy Ohlsson, He Zhang

    We perform a detailed study of the renormalization group equations in the inverse seesaw model. Especially, we derive compact analytical formulas for the running of the neutrino parameters in the standard model and the minimal supersymmetric standard model, and illustrate that, due to large Yukawa coupling corrections, significant running effects on the lept

  86. Samarth Chandra, Kabir Ramola, Deepak Dhar

    We analyse the low temperature properties of a system of classical Heisenberg spins on a hexagonal lattice with Kitaev couplings. For a lattice of 2N sites with periodic boundary conditions, we show that the ground states form an (N+1) dimensional manifold. We show that the ensemble of ground states is equivalent to that of a solid-on-solid model with contin

  87. Hung-Liang Lai, Joey Huston, Zhao Li, Pavel Nadolsky

    We examine the dependence of parton distribution functions (PDFs) on the value of the QCD coupling strength $α_{s}(M_{Z})$. We explain a simple method that is rigorously valid in the quadratic approximation normally applied in PDF fitting, and fully reproduces the correlated dependence of theoretical cross sections on $α_s$ and PDF parameters. This method is

  88. Zhi-Wei Sun

    In this paper we initiate the study of products and sums divisible by central binomial coefficients. We show that 2(2n+1)binom(2n,n)| binom(6n,3n)binom(3n,n) for every n=1,2,3,... Also, for any nonnegative integers $k$ and $n$ we have $$\binom {2k}k | \binom{4n+2k+2}{2n+k+1}\binom{2n+k+1}{2k}\binom{2n-k+1}n$$ and $$\binom{2k}k | (2n+1)\binom{2n}nC_{n+k}\bino

  89. Jason D. Bates, Paul R. Anderson

    Effects of quantized free scalar fields in cosmological spacetimes with Big Rip singularities are investigated. The energy densities for these fields are computed at late times when the expansion is very rapid. For the massless minimally coupled field it is shown that an attractor state exists in the sense that, for a large class of states, the energy densit

  90. Adrian Keet, Ben Fortescue, Damian Markham, Barry C. Sanders

    We present a unified formalism for threshold quantum secret sharing using graph states of systems with prime dimension. We construct protocols for three varieties of secret sharing: with classical and quantum secrets shared between parties over both classical and quantum channels.

  91. I. Pillitteri, S. Sciortino, E. Flaccomio, B. Stelzer

    X-rays from very young stars are powerful probes to investigate the mechanisms at work in the very first stages of the star formation and the origin of X-ray emission in very young stars. We present results from a 500 ks long observation of the Rho Ophiuchi cloud with a XMM-Newton large program named DROXO, aiming at studying the X-ray emission of deeply emb

  92. Leandro G. Almeida, Christian Sturm

    Light quark masses can be determined through lattice simulations in regularization invariant momentum-subtraction(RI/MOM) schemes. Subsequently, matching factors, computed in continuum perturbation theory, are used in order to convert these quark masses from a RI/MOM scheme to the MS-bar scheme. We calculate the two-loop corrections in quantum chromodynamics

  93. C. -C. Chen, J. Maciejko, A. P. Sorini, B. Moritz

    A growing list of experiments show orthorhombic electronic anisotropy in the iron pnictides, in some cases at temperatures well above the spin density wave transition. These experiments include neutron scattering, resistivity and magnetoresistance measurements, and a variety of spectroscopies. We explore the idea that these anisotropies stem from a common un

  94. Yuriy V. Skrypnyk, Vadim M. Loktev

    The electrical conductivity of graphene containing point defects is studied within the binary alloy model in its dependence on the Fermi level position at the zero temperature. It is found that the minimal conductivity value does not have a universal character and corresponds to the impurity resonance energy rather than to the Dirac point position in the spe

  95. Gwonchan Yoon, Sungsoo Na, Kilho Eom

    Single-molecule mechanical manipulation has enabled the quantitative understanding of the kinetics of bond ruptures as well as protein unfolding mechanism. Single-molecule experiments with theoretical models have allowed one to gain insight into free energy landscape for chemical bond and/or protein folding. For mechanically induced bond rupture, the bond-ru

  96. H. Casini

    We investigate the question of whether the entropy and the Renyi entropies of the vacuum state reduced to a region of the space can be represented in terms of correlators in quantum field theory. In this case, the positivity relations for the correlators are mapped into inequalities for the entropies. We write them using a real time version of reflection pos

  97. M. Sadiq Ali Khan

    The goal of an Intrusion Detection is inadequate to detect errors and unusual activity on a network or on the hosts belonging to a local network by monitoring network activity. Algorithms for building detection models are broadly classified into two categories, Misuse Detection and Anomaly Detection. The proposed approach should be taken into account, as the

  98. Evgeny Ivanov, Maxim Konyushikhin

    Using the harmonic superspace approach, we construct the three-dimensional N=4 supersymmetric quantum mechanics of the supermultiplet (3,4,1) coupled to an external SU(2) gauge field. The off-shell N=4 supersymmetry requires the gauge field to be a static form of the &#39;t Hooft ansatz for the 4D self-dual SU(2) gauge fields, that is a particular solution o

  99. Zachary Chance, David J. Love

    The use of open-loop coding can be easily extended to a closed-loop concatenated code if the channel has access to feedback. This can be done by introducing a feedback transmission scheme as an inner code. In this paper, this process is investigated for the case when a linear feedback scheme is implemented as an inner code and, in particular, over an additiv

  100. Joerg Kampen

    A global time-discretized scheme for the Navier-Stokes equation system in its Leray projection form is defined. It is shown that the scheme converges to a bounded global classical solution for smooth data which have polynomial decay at infinity. Furthermore, the algorithm proposed is extended to the situation of initial-boundary value problems. Algorithms co